Precision feeder for dynamic strand testers



Sept. 26, 1967 J. B. LAWSON 3,343,738

PRECISION FEEDER FOR DYNAMIC STRAND TESTERS Filed April 29, 1965 3 Sheets-Sheet 1 INVENTOR. JOHN B LAWSON ATTORNEYS Sept. 26, 1967 J. B. LAWSON 3,343,738

PRECISION FEEDER FOR DYNAMIC STRAND TESTERS Filed April 29, 1965 3 Sheets-Sheet 2 INVENTOR. JOHN B LAWSON BY 0 ml $941 ATTORNEYS Sept. 26, 1967 J. B. LAWSON 3,343,738

PRECISION FEEDER FOR DYNAMIC STRAND TESTERS Filed April 29, 1965 3 Sheets-Sheet 5 FIG?) FIG 4 WIN INVENTOR. 1 JOHN B. LAWSON ATTORNEYS United States Patent 3,343,738 PRECISION FEEDER FOR DYNAMIC STRAND TESTERS John B. Lawson, 368 New Meadow Road, Barrington, RI. 02806 Fiied Apr. 29, 1965, Ser. No. 451,733 4 Claims. (Cl. 22630) It is known that accurate dynamic testing of yarn or like strand material is possible only when the tension variations on said yarn or strand being tested is of known value as it enters the tester. Uneven tension on the strand as itpulls from the package, if allowed to reach the tester is a source of error that may be magnified in the testing system.

A purpose of this invention is to provide a feeder that will draw yarn or strand material from the package on which it is found and pass it to a dynamic testing machine under a known and accurately reproducible constant tension.

Another purpose is to provide a feeder that is self-powered, but will accommodate itself to the speed demands of the tester. Thus, the feeder may be moved to different instruments as desired.

A further purpose of this invention is to permit the tension on the strand to be controlled through the use of standard weights. Tensions thus controlled may be duplicated at will by the tester, so the test may be duplicated on another tester at a different location.

Still another purpose is to permit adjusting of the weight controlled element that applies the tension so the weight will apply the same degree of tension on the strand re gardless of the speed at which said strand is being furnished to the tester. A feature of this new tester is that it will feed either so-called inelastic or highly elastic yarns as desired.

A further purpose is to feed yarn positively and at a pre-selected tension to a testing machine regardless of variations in tension on the yarn or strand as it comes from the package. A yarn sensing means controls the rate of yarn feed and the tension on the yarn with the aid of a power assist. The power assist operates the necessary controls of the feeder in such manner that no significant change of tension will be imposed on the yarn sensing means and therefore, on the yarn being fed.

Other features and objects of the present invention will become apparent from a consideration of drawings wherein FIG. 1 is an elevation view in perspective of the feeder.

FIG. 2 is similar to FIG. 1, except that the parts have been exploded for better understanding.

FIG. 3 is a view partly in section of the power assist control.

FIG. 4 is a plan view of the pistons in the power assist control, with certain parts broken away.

The term without effort as used in this application does not mean the theoretical condition without any eX- penditure of energy impractical of realization, but rather a fractional change in the force applied to the delivered yarn to tension it which will be in the range where the practical operator will consider that it has no practical effect on his test results.

The feeder shown in FIG. 1 comprises a feeder roll 1 and a spiralling roll 2 with an axis that is at an angle to the axis of roll 1. Yarn or stranded material Y passes from a package thru guide 3 onto drum 1 from a guide 4 that may include a friction, tension 5, if desired. The

strand thus guided onto drum 1 locates itself in a plane normal to the axis of said spiralling roll. Since the axes of drum 1 and roll 2 are at an angle, one to the other, planes normal to their axes will be at an angle to one another. Thus, the strand coming from roll 2 back onto drum 1 will be moved a distance equivalent to a distance corresponding to the base of a triangle whose apex is the intersection of the planes normal to the axes at the point where the strand leaves roll 1 and enters onto roll 2, and whose legs continue within their respective planes a distance approximately equal to /3 the diameter of roll 2. Rolls of this type are well known in the textile industry and are sometimes referred to as Gaudet rolls. The rolls of my feeder are caused to have a common surface speed by connecting them with an elastic belt which drives roll 2 from drum 1. The yarn or strand is wound a sufficient number of times around these drums to precludeslippage.

Drum 1 is mounted on the output shaft of a variable speed mechanism 10, driven by an electric motor 11. Any variable speed device may be chosen which is capable of having its output speed reduced to zero and is also capable of accelerating to full speed in synchronism with the demand for the strand material and decelerating in accordance with cessation of demand of said strand material. I have chosen the well known Speed-Mate variable speed drive, driven by its own motor and manufactured by The Speed-Mate Co. of Minneapolis, Minn., for the purpose of illustrating my invention. Other units could have been chosen, including hydraulic motors or electronically controlled motors. The Speed-Mate drive derives power from its attached motor 11 that drives at a constant speed eccentric cam 12 keyed to motor shaft 13. Cam 12 oscillates a se ries of arms 14 (one only of which is shown in FIG. 2), such that said arms are moving non-synchronously. Arms 14 are constructed to move one-way clutches 15 at the end, remote from cam 12. There is a one-way clutch 15 for each arm 14, thus, there are a series of one-way clutches oscillating out of phase on a shaft 20. The one-way clutch is made up of the usual rolls 21 urged into wedging contact between outer ring 22 and shaft 2! by springs 23. Thus, shaft 20 will move thru an arc determined by the motion given the one-way clutches by their controlling levers. Since each lever is moving its one-way clutch in a direction to turn shaft 20 for a given period of time, depending on the speed of the motor 11, which is uniform, it therefore follows that the greater arc the one-way clutches are turned thru, the faster will be the speed of shaft 20 and therefore, drum 1.

Levers 14 are fulcrumed on cam 30 carried by a lever 31. Cam 30 may be raised, as viewed in FIG. 2, till it is opposite the position where levers 14 are connected to their one-way clutches 15, in which position the lower part of levers 14 will oscillate under influence of cam 12 without moving one-way clutches 15. Thus, shaft 20 will be stationary. When cam 30 is moved downward as viewed in FIG. 2, one-way clutches 15 will move thru an are turning shaft 20. The lower cam 30 moves, the greater are the one-way clutches will oscillate thru in a given length of time, thus causing shaft 20 to turn faster, and with it drum 1,- which is fastened thereto, and which delivers yarn or strand Y as demanded.

Lever 31 is fastened as by welding to shaft 32, the other end of said shaft being fastened as by welding to a second lever 34. This second lever is connected by an adjustable screw link 36 to a lever 40 having a ball 42 on its end which fits into a socket 44 in connection 36,

permitting free motion so lever 34 will be moved by lever 40.

Lever 40 is fastened to a shaft 50 that is journaled near its ends at 52 and 54 respectively. Shaft 50 is oscillated by levers 60 and 60' that are connected to it in such a way as to straddle an air cylinder 62, a part of the power assist system. A double ended piston 64 having a reduced end 66 and a large end 68 moves in the cylinder 62, preferably by compressed air in a manner that will be hereafter explained. Rods 70 are threaded into screw holes 71 in the metal connecting the two piston heads 66 and 68 and passes out thru elongated openings 72 located on each side of the cylinder. Ball or roller bearings 74 are located on the rods 70 and fit in the slots 72 to provide for easier motion. Rods 70 project into fork openings 76 atop levers 60 to oscillate them and thus, shaft 50.

Referring now to FIG. 3, the piston having small end 66 and large end 68 has fitted to its respective ends synthetic rubber membranes 80 for the small end 66 and 82 for the large end 68. These membranes known a Belloframs and manufactured by Bellofram Corp, Burlington, Mass, have flanges 84 and 86 that are held between the main body of the cylinder 62 and the heads 90 and 92 that close it off.

Full line air pressure is introduced between the head 90 and membrane 80 for the small size piston 66 thru pipe 94 that branches from main line pipe 96. At the other end of the cylinder, air is introduced thru a nozzle 100 having an orifice approximately .010" in diameter, into the space between head 92 and membrane 82. Air then passes thru a passageway 102 along the axis of piston 68 to a nozzle 104. Nozzle 104 may be closed by clapper valve 106 pivoted on shaft 108. Nozzle 104 has an opening larger than nozzle 100, preferably about three times as large as the opening in said nozzle 100.

Between pistons 68 and 66 there is a rectangular opening best seen in FIG. 4. Nozzle 104 extends thru piston end 68 into this opening, and the air escaping from this nozzle 104 is controlled by the clapper valve 106 pivoted on shaft 108 which shaft extends from one side to the other in this rectangular opening. Protuberances 109 and 109' extend from the side walls of the rectangular opening and shaft 108 passes thru the approximate center of these protrusions which have a near circular contour where they abut against clapper valve 106 to hold said clapper valve away from the sides of the opening, thereby permitting the clapper valve to pivot very freely about its shaft 108.

If clapper valve 106 is in position to close nozzle 104, then the air pressure per square inch will be the same at the end of piston 66 and piston 68. However, piston 68 is larger in diameter than piston 66 and thus, the resultant force will be such as to move piston 68 to the left as seen in FIG. 3, so that piston 66 will move closer to head 90 against the air pressure operating on said piston 66. In other words, the piston will move to the left as viewed in FIG. 3 as long as clapper valve 106 re mains in a position to close nozzle 104. When clapper valve 106 is opened, it will permit the air pressure in back of piston 68 to be so reduced that the air pressure in back of piston 66 will force the assembly of pistons to the right. It will be readily seen therefore, that there is an intermediate position that clapper valve 106 can occupy where it will permit enough air to flow from nozzle 104 so that the resultant force on both pistons 66 and 68 will be equal and of course opposite, with the result that the assembly will be stationary.

Clapper valve 106 is biased toward nozzle 104 by a spring 110 that causes said valve to turn about shaft 108 on which said clapper valve 106 is pivoted in a direction so as to close said nozzle 104. Spring 110 is made up of two sets of coils 111 and 111 separated by a U shaped portion 113 that presses against the clapper valve 106 to urge it in contact with nozzle 104. The two ends or legs 114 of the spring that extend from the coils 111 and 111 are held by a rod 116 to keep the coils from unwinding. This action holds U connection 113 in contact with clapper valve 106.

Referring now to FIGS. 1 and 2, it will be seen that there is a rod 120 having at one end a pulley 122 supported in a U shaped housing 124, while the other end of said rod 120 passes thru a block 126 in which it is clamped by screw 128. This rod 120 is positioned by the loop of yarn Y and senses the length of said loop. Block 126 is supported for rotation on a shaft 130 that extends at right angle from it as compared to yarn sensing rod 120. Shaft 130 is journaled in a U-shaped bracket 132, which bracket is held near the end of shelf 134 farthest removed from drum 1. A counterbalance weight 136 is held adjustably by screw 138 on the end of yarn sensing rod 120 that protrudes thru block 126. A block 140 is clamped to rod 120 between pulley 122 and pivot block 126, a short distance from said pivot block 126. Depending from block 140 by means of a pivoted connection 144 is a disk 146. Disk 146 sinks into a cup 150 filled with a semi-viscose fluid such as oil, so as to resist a sudden up or downward movement as viewed in FIG. 1 or 2.

Supported on shelf 130 above cylinder 62 is a slide held in position by pilot screw 162 that projects into slot 164 while a clamping screw 166 passes thm slot 168 and holds said slide 160 in position on plate 134. At or near the center of slide 160 is a cross slot 170 for reception of protuberance 172 on lever 174. Lever 174 pivots on stud 176, said stud being held in block 178, which in turn is fastened to shelf 134 by screws 179. Lever 174 has extending from its end furthest removed from pivot 176 a stud 180 adapted to support rod 120 when said rod has dropped to its lowest point or turned counter clockwise as seen in FIGS. 1 and 2. Stud 180 also provides a convenient means for moving lever 174 and hence, slide 160. Thus, as slide 160 is moved to the left as seen in FIGS. 1 and 2, lever 174 with its stud 180 is lowered, and vice versa.

At the rear of slide 160 or to the right as seen in FIGS. 1 and 2 is fastened a U support at the end of a leaf 191. This U bracket supports for rotation a shaft 192 which in turn supports a drum 194 fastened to said shaft where it protrudes beyond bracket 190. At the other side of bracket 190, shaft 192 is provided with a series of right angle bends as it projects from said bracket 190. This series of right angle bends forms a U, the bottom 196 of which extends over and is rotated by rod 120, as it rests thereon. This means that shaft 192 and drum 194 will be rotated back and forth in synchronism with the movement of yarn sensing rod 120. Drum 194 carries on its rim a chain or nylon cord that is attached to clapper valve 106 at 198 as seen in FIG. 1 so as to rotate clapper valve 106 about its pivot 108 and away from nozzle 104 to permit air to escape when sensing rod 120 lowers.

When yarn sensing rod 120 is raised by shortening the loop of yarn Y in which it rests due to demand for yarn at a greater rate of speed, drum 194 will be rotated clockwise by reason of portion 196 of the shaft 192 on which it is mounted being moved upward by said sensing rod 120. Such clockwise rotation of drum 194 releases tension on chain 198 permitting clapper valve 106 to close nozzle 104, thus causing piston 68 to move to the left increasing the speed of drum 1. Dropping of yarn sensing rod 120 permits 196 to drop, causing drum 194 to move counter clockwise to open nozzle 104 so piston 68 will move to the right and slow delivery of strand Y. Thus, raising of yarn sensing rod 120 increases the tension force on yarn Y only to the extent due to the inertia of raising U portion 196. Clapper valve 106 is opened against its spring pressure by U portion 196 following sensing rod 120. Such control requires only a minor change in energy, especially since sensing rod 120 with all the weights upon it except W is counterbalanced to a level position at start of feeding and before yarn is placed on it. The bringing of sensing rod 120 back to a level position when it is feeding at the required rate assures that tension on yarn Y will be controlled by weight W and will be of the same magnitude at all times when weight W is the same. U portion 196 may overlie rod 120, or if spring 110 is made strong, then 196 may rest under rod 120,:being held in position by said spring 110.

To use the pre-feeder, the motor 11 is turned on by switch S and compressed air is supplied to-the power assist cylinder 62 thru pipe 96. counterbalance 136 is moved along yarn sensing rod 120 until said rod balances in a horizontal position. A weight W is hung on the hook 200 that extends from the bracket 124 for this purpose. Weight W may be as little as 1 gram or may be over 100 grams depending on the tension desired in the strand Y being fed. Weight W moves rod 120 dbwnward until it rests on stud 180. Downward movement of rod 120 causes the bottom 196 of the U bend of shaft 192 to move downward turning drum 194 counter clockwise so as to pull clapper valve 106 of the power assist away from nozzle 104, causing the combined piston 66-68 to move to the right as seen in FIGS. 1 and 2. Such motion of the piston causes shaft 50 to move clockwise raising lever 31 with its fulcrum block 30 upward so levers 14 will not move one-way clutches 15, and thus shaft 20 and drum 1 will be stationary.

Thread or yarn Y from its package will be led up thru suitable guides such as 3, a tension 5 if desired, and thence from a guide such as 4 onto drum 1. The thread or yarn Y will be wound around drum 1 and spiralling roll 2 a sufficient number of times so it will be pulled positively Without slippage from its package. Yarn or thread Y will then be led over stationarily positioned pulley 202 down around pulley 122 and thence over pulley 204 to the testing machine. Pulleys 202 and 204 are mounted on ball bearings as is pulley 122 and the U shaped brackets holding pulleys 202 and 204 are mounted on a bracket 206 extending from the pre-feeder frame.

When thread or yarn Y is demanded by the instrument being served, the loop of yarn Y in which yarn sensing rod 120 rests will be shortened, raising pulley 122 and rod 120. Such lifting action causes U loop 196 to rise, rotating drum 194 clockwise, permitting clapper valve 106 to close nozzle 104 due to the action of spring 110 and its various parts. Closing of nozzle 104 in the power assist will cause a buildup in pressure under piston 68, forcing it to the left to thus turn shaft 50 counterclockwise. Such action will cause lever 31 to move its fulcrum block 30 downward on levers 14 causing them to oscillate and thus in turn oscillate one-way clutches 15 so as to turn drum 1. The faster yarn Y is demanded, the higher pulley 122 will be lifted so as to in turn cause faster rotation of drum 1.

After the system is in equilibrium, which occurs when drums 1 and 2 are turning fast enough to deliver yarn Y at the required rate, yarn sensing rod 120 with its pulley 122 may be brought to a level position where weight W will have full right angular effect on the thread tension. This is accomplished by loosening clamp 166 and moving slide 160 backward or forward. Movement of slide 160 will cause movement of clapper valve 106 due to the moving of drum 194, and this will affect the speed of drum 1 in the manner described above. If yarn sensing rod 120 is higher than a level position, then slide 160 will be moved to the left as seen in FIGS. 1 and 2, causing piston 68 to move to the left by releasing chain 196 which in turn permits clapper valve 106 to close nozzle 104, resulting in the turning of shaft 50' and the lowering of lever 31 causing a speed up of drum 1, permitting yarn sensing rod 120 to drop to slow the thread back to the demanded speed. The movement is continued for slide 160 until yarn sensing rod 120 at its level position causes drum 1 to turn sufiiciently fast to furnish the yarn desired by the testing machine being served.

When disk 146 is lifted, liquid flows from its top surface past its sides into cup 150. This action provides a dampening effect that prevents yarn sensing rod over rising during starting of the testing machine. This dampening action also prevents pulley 122, when controlled by a heavy weight W, from bouncing while feeding an elastic yarn. In other words, it prevents the bouncing ball action of the Weighted pulley 122. A fluid controlled power assist means has been described for adjusting the driven means so as to positively draw yarn from its package and delivering it to the testing machine being served. Other power assist means may be used without departing from the invention. For example, instead of fluid means by which it is intended to cover use of both gases and liquids under pressure, electronic means may be used between the yarn sensing rod and variable speed mechanism so that the forces acting to tension the yarn will not include forces acting directly on the variable speed controls as disclosed for example in the Robert H. Lawson Patent #2,227,356.

In the drawing and specification, there have been set forth preferred embodiments of the invention and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a feeding apparatus for supplying a strand of material to a testing machine or the like, said apparatus having a frame and including a feed drum rotatably supported by said frame, means for guiding said strand from its source of supply about said feed drum, and variable speed drive means for rotating said feed drum to advance the strand to the testing machine, said drive means including movable speed regulator means, the movement of which determines the rotational speed imparted to said drum, and a movable strand tensioning arm pivotally mounted upon said frame for forming said strand into a loop between said feed drum and said testing machine, that improvement comprising means for adjusting the rotational speed of said feed drum to maintain the rate at which the strand is fed in balance with the rate at which the strand is demanded by said testing machine including, in combination:

(a) a cylinder supported by said frame,

(b) a piston movably disposed within said cylinder and means for forming a first hermetically sealed chamber within said cylinder, adjacent one end of said piston,

(0) means for supplying hydraulic fluid into said first sealed chamber under suflicient pressure to move said piston,

(d) valve means connected to said piston and movable therewith for governing the flow of hydraulic fluid into said first chamber,

(e) means operatively connecting the strand tensioning arm to said valve means whereby any movement in the arm creates an immediate and proportional movement of said valve, and

(f) linkage means operatively connecting said piston to said speed regulator means for said drive means whereby said speed regulator means is moved simultaneously and proportionately as said piston moves in response to a change of hydraulic pressure in said chamber induced by movement of the valve by the tensioning arm.

2. The invention of claim 1 further including means for forming a second hermetically sealed chamber within said cylinder adjacent the opposite end of said piston, and means for supplying hydraulic fluid therein.

3. The invention of claim 2 wherein the end of said piston adjacent said first chamber is larger than the end of said piston opposite thereto.

7 4. The invention of claim 3 wherein: (a) said piston contains an opening between its opposing ends, i (b) a hollow conduit is formed through said larger end of said piston which terminates in a nozzle venting into said opening whereby hydraulic fluid may escape from said first chamber, and

(c) said valve is disposed in said opening adjacent said nozzle.

2 8 References Cited UNITED STATES PATENTS 2,744,408 5/ 1956 Seney 7 3160 X 3,071,300 1/1963 Justus 226-44 X FOREIGN PATENTS 918,073 2/ 1963 Great Britain.

M. HENSON WOOD, JR., Primary Examiner. R. A. SCHACHER, Assistant Examiner. 

1. IN A FEEDING APPARATUS FOR SUPPLYING A STRAND OF MATERIAL TO A TESTING MACHINE OR THE LIKE, SAID APPARATUS HAVING A FRAME AND INCLUDING A FEED DRUM ROTATABLY SUPPORTED BY SAID FRAME, MEANS FOR GUIDING SAID STRAND FROM ITS SOURCE OF SUPPLY ABOUT SAID FEED DRUM, AND VARIABLE SPEED DRIVE MEANS FOR ROTATING SAID FEED DRUM TO ADVANCE THE STRAND TO THE TESTING MACHINE, SAID DRIVE MEANS INCLUDING MOVABLE STRAND TENSIONING ARM MOVEMENT OF WHICH DETERMINES THE ROTATIONAL SPEED IMPARTED TO SAID DRUM, AND A MOVABLE STRAND TENSIONING ARM PIVOTALLY MOUNTED UPON SAID FRAME FOR FORMING SAID STRAND INTO A LOOP BETWEEN SAID FEED DRUM AND SAID TESTING MACHINE, THAT IMPROVEMENT COMPRISING MEANS FOR ADJUSTING THE ROTATIONAL SPEED OF SAID FEED DRUM TO MAINTAIN THE RATE AT WHICH THE STRAND IS FED IN BALANCE WITH THE RATE AT WHICH THE STRAND IS DEMANDED BY SAID TESTING MACHINE INCLUDING, IN COMBINATION: (A) A CYLINDER SUPPORTED BY SAID FRAME, (B) A PISTON MOVABLY DISPOSED WITHIN SAID CYLINDER AND MEANS FOR FORMING A FIRST HERMETICALLY SEALED CHAMBER WITHIN SAID CYLINDER, ADJACENT ONE END OF SAID PISTON, (C) MEANS FOR SUPPLYING HYDRAULIC FLUID INTO SAID FIRST SEALED CHAMBER UNDER SUFFICIENT PRESSURE TO MOVE SAID PISTON, (D) VALVE MEANS CONNECTED TO SAID PISTON AND MOVABLE THEREWITH FOR GOVERNING THE FLOW OF HYDRAULIC FLUID INTO SAID FIRST CHAMBER, (E) MEANS OPERATIVELY CONNECTING THE STRAND TENSIONING ARM TO SAID VALVE MEANS WHEREBY ANY MOVEMENT IN THE ARM CREATES AN IMMEDIATE AND PROPORTIONAL MOVEMENT OF SAID VALVE, AND (F) LINKAGE MEANS OPERATIVELY CONNECTING SAID PISTON TO SAID SPEED REGULATOR MEANS FOR SAID DRIVE MEANS WHEREBY SAID SPEED REGULATOR MEANS IS MOVED SIMULTANEOUSLY AND PROPORTIONATELY AS SAID PISTON MOVES IN RESPONSE TO A CHANGE OF HYDRAULIC PRESSURE IN SAID CHAMBER INDUCED BY MOVEMENT OF THE VALVE BY THE TENSIONING ARM. 